Material handling crate with magnetic coding plates



United States Patent Inventor Houston Rehrig 100 Los Altos Drive, Pasadena, California 91105 Appl. No. 722,029

Filed April 17, 1968 Patented Oct. 27, 1970 MATERIAL HANDLING CRATE WITH MAGNETIC CODING PLATES 33 Claims, 15 Drawing Figs.

Int. Cl. B65g43/00 Field of Search 214/1 1;

209/111.8: 198/38: 206/(Mag. Digest): 217/(lnquircd); 220/ 1(lnquired);,,40/3 12 [56] References Cited UNITED STATES PATENTS 2,980,235 4/1961 Mittag 198/38 3,100,040 8/1963 Kleist 214/11X 3,157,270 11/1964 Prucha 198/38 3,275,123 9/1966 Prosser.... 198/38 3,307,162 .2/1967 Fink 198/38X Primary ExaminerRichard A. Schacher Attorney-Beveridge & DeGrandi ABSTRACT: A crate suitable for use in a material handling system employing a conveyor capable of selectively delivering articles to a plurality of destinations, and magnetic destination coding and code-reading equipment. A sheet of magnetizable material is rigidly mounted to one panel of the crate in position to receive the magnetic code elements from the destination coding apparatus. The crate includes an improved structure for receiving and retaining the magnetic code, as well as improved means for positioning the crate with respect to the magnetic coding equipment.

Patented Oct. 27,1970 3,536,182

Sheet 2 014 H05 1 'mm HOUSTON REHRIG BY "r ATTORNEYS Patented Oct. 27, 1970 I 3,536,182-

* IIIIIIA'II- FIGIO rum/rm HOUSTON ammo 'I'ATTORNEYS Sheet Pa tehted 0a. 27, 1970 v mvmon HOUSTON 'mzume monuevs MATERIAL HANDLING CRATE WITII MAGNETIC CODING PLATES This invention relates to material handling crates, and more particularly to an improved crate suitable for use in an automatic material handling system employing magnetic destination coding and code-reading equipment. It is well known to employ conveying systems to distribute articles from a central location to any one of a plurality of receiving stations, selectively, in accordance with a magnetic destination code carried by or which accompanies the article to be conveyed. Such systems may employ any of the conventional types of conveyors and the magnetic destination coding or routing information carried by the articles may be employed to effect the remote control actuation of various elements of the conveyer system, as a consequence of the specific information carried bythe article, in accordance with any predetermined program to deliver the article to the desired location.

It is contemplated that similar systems may be employed in warehousing and distribution systems in which various products are automatically delivered either to the desired location at a loading or. distribution dock or to a storage warehouse, with the magnetic identification code being retained on the crates carrying the product directed to the storage areas so that the material can subsequently be auto matically withdrawn from the storage area and directed to the desired location at the distribution dock.

The economical utilization of warehouse storage space in such a system would normally require that the product be stored in vertically stacked relation, with the adjacent stacks being positioned as closely as possible to one another. This, of course, presents a problem in reading the magnetically coded information on the articles in storage. Further, when products are to be stored for a substantial period of time, it is essential to the operation of such a system that the magnetic code be clearly retained throughout the storage, so that the material may reliably and accurately be recalled from storage for distribution by the system.

In many industries, such as the food processing or dairy industries, for example, crates employed to handle the product must be repeatedly subjected to conditions whichare highly conducive to corrosion or oxidation of the magnetic code carrying elements, so that'the ability to retain a magnetic code may be greatly impaired after extended or repeated use.

It is a primary object=of the present invention to provide an improved material handling crate which overcomes many of the defects of crates previously employed in automatic material handling systems. To this end, a crate embodying the invention employs one or more rigid sheets of magnetizable material permanently secured in fixed relation on one panel of the crate in position to receive a magnetic code printed thereon. This magnetic code is employed, through suitable magnetic reading and electrical relay systems, to control movement of the crate throughout the system, including storage and subsequent dispatch from storage. The construction is such as to protect the magnetizable sheets from damage during normal handling, cleaning, refrigerated storage, or the like. In addition, the crate may also include means to facilitate the accurate orientation of the crate with respect to the encoding and code-reading apparatus.

Other objects and advantages of the invention will be more fully apparent from the following description taken in connection with the accompanying drawings wherein like reference numerals have been employed to refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a fragmentary perspective view of a crate embodying the present invention and positioned on a roller conveyer;

FIG. 2 is a top plan view of the crate shown in FIG. 1, with parts broken away to more clearly illustrate other parts;

FIG. 3 is a sectional view taken on line 34 of FIG. 2;

FIG. '4 is an enlarged, fragmentary bottom plan view of a portion of the bottom panel of the crate shown in FIG. 1, with certain parts broken away to more clearly illustrate other parts, and illustrating an alternate embodiment of the magnetizable code-receiving element;

FIG. 5 is a view similar to FIG. 4, ma smaller scale, and illustrating a further embodiment of the invention;

FIG. 6 is an enlarged sectional view taken on line 6-6 of FIG. 5;

FIG. 7 is a perspective view of a magnetizable code-receiv- FIG. 11 is a bottom plan view of the cup-shaped insert shown in FIG. 10;

FIG. 12 is a bottom plan view of the crate illustrating a further embodiment of the invention;

FIG. 13 is an enlarged fragmentary partially exploded sectional view taken on line 13-13 of FIG. 12;

FIG. 14 is an enlarged fragmentary view of a portion of .the crate illustrated in FIG. 12; and

FIG. 15 is a schematic illustration of a portion of a material handling system employing applicants improved material handling crate.

Referring now to the drawings in detail, appllcants invention will be described as embodied in a crate. suitable for use in an automatic material handling system of the type employed in a modern dairy plant. It will be understood, of course, that crates embodying the invention may be employed for various uses, and specific reference to the dairy industry or dairy crates is made only by way of example, it being understood 7 that the structure of the cratevrnay readily be modified as necessary or desirable to adapt them for use in any material handling system of the general type described hereinbelow. In such a system, it is contemplated that the filled containers of dairy products will be crated, with the crates being stacked at the filling apparatus in vertical stacks containing up to six or more crates of a particular product. The stacks of crated product will then be released onto a conveyer for movement past an encoder where a magnetic code will be printed onto the lowermost crate only, which code will vary depending on the product and desired destination of the'stack. The stack will then be automatically delivered to the desired area of a refrigerated storage. facility in accordance with a predetermined program. The stored product may later be recalled from storage in any combination of stacks desired, for example as required to make up a route delivery load, and directed to the desired dock area automatically.

When the empty crates are returned to the plant, they are cleaned and magnetically decoded, then returned to the system for reuse.

Referring first to FIG. 1, a material handling crate of the general configuration conventionally employed to handle a plurality of cartons or bottles of milk is indicated generally by the reference numeral 10, and includes abottom panel 11, opposed side panels 12, I3 and opposed end panels 14,15 with the respective panels being joined along their contiguous edges. Preferably at least the bottom panel is molded from a synthetic resin material and formed with a plurality ,of openings 16 extending therethrough, the openings 16 being necessary 'in the dairy industry to provide drainage from the crate and to permit circulation of air through the crate, particularly during refrigeration. In the embodiments of the invention illustrated in FIGS. 1-4, the bottom panel 11 is integrally molded in the form of an open grid made up of a plurality of perpendicularly arranged web members 17 having a somewhat enlarged, flat top portion 18 defining the top surface of the bottom panel 11. The grid elements, or webs l7, defining the rectangular area 19 in the central portion of the end panel 11 have a notch 20 formed in their lower, inner edge defining a horizontal shoulder 21 (see FIG. 4) spaced vertically above the bottom edge of the bottom panel'll. The web members 22 within this rectangular area are somewhat shorter than those outside the area, terminating at the level of the shoulder 21, and are joined at the top edge by a continuous substantially flat integrally molded sheet 23 of the synthetic resin material. Thus, the webs 22 and the shoulder 21 form, in effect, a recess in the bottom surface of panel 11. A thin rectangular plate 25 of magnetizable material is supported in this recess on the shoulder 20 and the bottom surfaces of the short web members 22. Sheet 25 is of a magneti cally hard material such as watch spring steel, and may be approximately .0l inches in thickness. Sheet 25 is retained in position and hermetically sealed within the bottom panel by a sheet 26 of synthetic resin material bonded, as by heat sealing, within the notch 20. Also, if desired, the sheet 25 may be bonded to the bottom surfaces of the webs 22 and to the shoulder 21, with the cover sheet 26 being bonded to the bottom surface of the sheet 25. Preferably the bottom surface of the cover sheet 26 is coplanar with the lower surface of the bottom panel 11, with a stacking rail 28 of conventional construction extending around the outer periphery of the crate and projecting downwardly below bottom panel 11 to normally support the bottom panel above a supporting surface, thereby reducing the likelihood of damage to the code-carrying portion of the crate. If desired, the sheet 25 of magnetizable material may be coated before assembly with a rustprohibiting material such as lacquer, or the like, as a further insurance against rusting or corrosion of the plate.

Referring again to FIG. 1, the crate described above may be conveyed along a horizontal path by suitable conveyer means such as the roller conveyer 30, and urged into side edge alignment with afixed horizontal guide 31 by a resiliently biased guide rail 32. As the crate passes over the destination encoding element illustrated diagramatically at 33, a retractable stop 34 is projected into the path of the crate to hold the crate for a predetermined time in fixed position above the encoding element 33, during which time the desired code in the form of a patterned magnetization such as a group of dipoles each preferably aligned with the direction of travel of the crate along the conveyer 30, and at a desired spacing, for example one dipole to each coding segment 42, illustrated in FIG. 4. In a thin plate, a large number of dipoles may be employed, but with the disadvantage that too close spacing may not give sufficient permanency or definition when it is decoded or read. As shown in FIG. 3, the stacking ring 28 extends around the entire crate in that, as the crate passes over the encoding device 33, the code-carrying plate (or plates) is spaced at a fixed, substantial distance above the encoding device. For example, in a typical milk crate of the type commonly employed by the dairy industry, this spacing may be as much as three-eighths inch, or more. In view of the magnitude of this spacing, it becomes essential that the spacing be maintained constant, both over the encoding .and the readout equipment (not shown).

Again referring to FIG. 1, once a crate has been encoded, it is released by the stop 34 and permitted to continue'its movement along the conveyer path, with its destination and routing in the system from this point being determined by the magnetic code symbols carried on the plate 25. Since the crate passes over the top of the encoding apparatus and the code reading apparatus, and further since the code carrying plate 25 is spaced a substantial distance above the plane .of the con veyer, the individual code signals must necessarily be of substantial magnetic strength in order to be accurately interpreted by the magnetic readout equipment as thecrate passes thereover. However, there is a tendency of these relatively strong magnetic code symbols to merge, or dissipate themselves within the body of the magnetic material, particularly where a relatively large number of the code symbols are implanted on a single sheet of code-carrying material and where the code is stored within the material for a substantial period of time. It has been found, however, that this tendency for the code symbols to merge can, be reduced by segmenting the sheet of code-carrying material into a plurality of welldefined individual code receiving areas. I

Referring to FIG. 4, one means of reducingthc tendency of the magnetic code symbols to dissipate is illustrated. In this embodiment, the sheet 40 of magnetizable material has a plurality of elongated, narrow slots 41 extending completely therethrough, with the slots.41 being arranged in rows dividing the sheet 40 into a plurality of rectangular coding segments 42. The coding segments 42 are integrallyjoined at their ad- I jacent corners by relatively thin narrow tab portions 43. Preferably the elongated narrow slots 41 are arranged to correspond to the spacing of the web members 22 so that, when the sheet 40 is installed in the recess'in the bottom of panel 1 l, the cover sheet 26 may be bonded to the webs 22 through the eleongated slots 41 to provide strength and rigidity to the panel 11. Such a bond through the slots 41 forms, in effect, a complete hermetic seal for the individual coding segments 42, with a dead air space or chamber 44 in the bottom panel (see FIG. 6) between the coding segment 42 and the top cover 23.

In FIGS. 5-7 a further embodiment of the invention is shown in which a plurality of separate sheets 45 of magnetiza? ble material are mounted within the bottom panel 11. The individual sheets 45 each comprise four separate rectangular coding areas 46 arranged in spaced coplanar relation to one another, with the separate coding areas 46 being joined together with integrally formed thin web members 47. Preferably the sheets 45 are stamped from a single rectangular blank or sheet of flat steel material, with the individual coding areas 46 defining the four corners of the blank and with adjoining coding. areas being separated by a distance substantially equal to the width of the individual coding areas.

In the embodiment illustrated in FIG. 5, four of the magnetizable sheets 45 are mounted in the bottom panel I], with each individual sheet 45 being sealed within a separate recess in the bottom panel by individual cover sheets 48. Further, the individual sheets 45 are spaced from one another by a distance substantially equal to the spacing of the individual coding areas 46, thus providing a uniform spacing of the individual coding areas throughout the code-carrying segment of the bottom panel 11. The spacing of the code-carrying areas 46 has been found to greatly reduce the tendency of the magnetic code symbols printed on the coding areas to merge or dissipate. It is believed that this reduced dissipation may result, at

least in part, from the separation of the flux fields of the individual code symbols.

Referring now to FIGS. 8-- 14, a further embodiment of the invention will be described in which means are provided for rigidly mounting sheets of magnetizable material within openings formed in conventional commercial crates such, for example, as the crate shown in US. Pat: No. 3,351,228 to I-Iuisman, assigned to the assignee of the present invention. This embodiment will be described first with particular reference to FIGS. 8-11, with the slightly different configuration of FIGS. 12-14 beingsubsequently pointed out. In this embodiment, separate cup-shaped containers 50 are provided for insertion, in an inverted position, into the individual drainage openings 16 in the bottom panel 11. The cups 50 are molded from synthetic resin material and each comprises an end wall 51 with integrally molded downwardly and slightly outwardly extending side walls 52 having an outer surface arranged to conform to the contour and snugly fit within the individual opening 17 in the bottom panel 11. A pair of wedge-shaped projections 53 are integrally formed on two of the opposing sidewalls 52 with the projections 53 tapering outward and downward from the end wall 51 and terminating in a horizontal shoulder 54 spaced above the open end 55 of the container. As illustrated in FIGS. 9 and 10, a complementary recess;56 is formed in opposing side surfaces of two of the webs 17, with the recesses 56 terminating in an upwardly directed shoulder 57. The cups 50 may be rigidly and permanently mounted within the openings 49 by inserting the cups into the openings from the bottom of panel 11, applying sufficient force tothe cup to cam the webs 17 apart sufficiently to permit the wedge-shaped protrusion 53 to snap into recesses 56 so that the shoulders 54 and 57 engage to positively lock 'the cup in position. In this position, the end wall 51 forms a smooth complementary continuation of the inner surface of a bottom panel 11. If desired the walls 52 may be bonded to the webs 17 to further retain the cups against removal. Also, this bonding, as by heat sealing,'may be desirable at least in the area indicated'by the arrow 49 in FIG. 9 to assure against accumulation of foreign matter on the bottom of the crate.

The cups 50 have a plurality of integrally molded, downwardly projecting web members 58 which terminate at a position spaced slightly above the bottom open edge 55 of the side walls 52. These webs 58 provide vertical support for rigid coding plates 59 in the form of sheets of magnetizable material positioned therein. The coding plates 59 are rigidly retained in the cups 50 by cover sheets 60 of synthetic resin material continuously bonded, as by heat sealing, around the open periphery 55 of the cups 50. As shown in F IG. 9, the cover sheets 60 are substantially coplanar with the lower surface of bottom panel 11 when the assembly is installed in the crate.

While the embodiment illustrated in FIGS. 8-11 illustrates that the invention may be employed with existing commercial crate designs, particular coding systems may not be well suited to the particular size, spacing, or configuration of coding plate 39 dictated by existing structures. However, as illustrated in FIGS. 12-l4 the concept of hermetically sealing the codecarrying metal sheet 59 in a separately formed cup or capsule, and subsequently mounting the capsule within a previously formed crate may be employed regardless of the configuration or spacing of the code-carrying elements. Thus, while the configuration of the bottom'panel may, to some extent, be dictated by the configuration of the coding elements desired, once the bottom panel 11 of the crate is determined, a user may then employ the same basic crate structure with or without the coding elements. Further, crates originally purchased for use in other systems may readily be converted for use in the automatic material handling system employing the magnetic coding arrangement briefly described hereinbelow.

In the arrangement illustrated in FIG. 12, which is simply a slightly different configuration of the structure shown in FIGS. 8ll, the crate is designed to pass over the magnetic coding and reading apparatus in a direction parallel to the longitudinal dimension of the individual magnetizable code-carrying sheets 59. For certain magnetic materials, this elongated rectangular configuration of the code-carrying element is found to be more satisfactory than the square elements illustrated in FIG. 9. Further, it has been found that the spacing of the elongated rectangular coding elements 59 may be less in the direction of their longer dimension than in the direction of the transverse dimension. The effect of this spacing upon the tendency for the magnetic code patterns to merge can be controlled by varying the spacing either parallel or transversely to the code symbol dipoles. Similarly, the total area as well as the shape of the individual code-carrying sheets have a definite effect upon the merging of the magnetic code symbols carried on the sheet.

While the individual coding plates 59 have been described as being mounted in the bottom panel 11 as a part of separately formed cup-shaped container assemblies, it is believed apparent that they could be mounted in the manner similar to that described with respect to the embodiments illustrated in FIGS. l7. Thus, any desired number of discrete coding plates could be mounted in any desired configuration or spacing, without the necessity of employing the cup assemblies.

Similarly, while the various embodiments particularly described have illustrated the coding plates mounted within a recess formed in one panel of the crate, it is believed apparent that they need not be embedded in the panel. For example, it is contemplated that the coding plates may be positioned on a flat surface and secured to the crate by an overlying cover sheet. Alternatively, the coding plates may be bonded between two rigid sheets of synthetic resin material, with the resulting sandwich structure being attached to and forming an integral structural part of one panel of the crate. Nor is it essential that the panel carrying the coding plates be the bottom panel of the crate, or that it be formed of synthetic resin.

Referring now to FIG. 15, a portion of a material handling L system in which the crates according to the present invention may be used will be briefly described. The system, schemati cally illustrated, includes a roller conveyer 30 driven to convey the individual crates 10 along a horizontal path from an infeed station (not shown) such as a conventional filling.-

machine employed in dairy plants'As the individual stacks of crates are driven along conveyer 30 in the direction of arrow 70, they first engage an orientation sensing and turning mechanism, indicated generally by the reference numeral 71 and operable to turn the crates as necessary to properly orient the magnetic coding plates in the bottom panel for accurate alignment and presentation to the encoding mechanism 33. The crate turning apparatus 71 comprises a spring-biased guide rail 72 positioned to engage and resiliently urge a crate moving on the conveyer into-side edge alignment with the fixed guide rail 31 extending along the opposite side of the conveyer. Each of the crates are formed with an outwardly directed flange 72 (see FIGS. 1-3) positioned adjacent the bottom of the crate and extending around the outer periphery thereof, and two locating notches 73 are formed in this flange, one adjacent the bottom of each of the side panels 12 and 13 and accurately located equal distance from the end walls 14 and 15. The fixed guide rail 31 is interrupted at the turning apparatus 71 and a resiliently biased sensing shoe 74 is interposed therein in position to engage and be laterally deflected by the flange 72 as a crate moves through the turning apparatus. Outward deflection of the sensing shoe 74 by a crate actuates a switch 75 which energizes a circuit to project a retractable stop 76 into the path of the crate at a position downstream from the turning apparatus and spaced laterally from the fixed guide 31 in position to engage and restrain one corner of the crate to turn the crate 90 on the conveyer in a manner well known in the art. A second sensing element 77 is mounted adjacent the resiliently biased shoe 74 and has a plunger element 78 adapted to project through the shoe 74 to engage the flange 72. The plunger 78 slides along the flange 72 as the crate moves through the turning apparatus so that, if the crate is oriented to present one of the sensing notches 73 in position to be engaged by the plunger, projection of the plunger into the sensing notch actuates a switch 79 which is connected into the electrical circuit with the switch 75 to retract the stop 76 and permit the crate to continue on the conveyer without being turned. However, if a sensing notch 73 is not encountered by the plunger 78, the stop 76 will remain in a raised position so that the crate will automatically be turned to properly orient the crate in the manner described above. An override switch 80 is positioned to be engaged by a crate moving through the turning apparatus to override any signal from the switch 79 resulting from movement of plunger 78 after the trailing edge of the crate has reached a predetermined point to thereby override any signal from the switch 77 as the trailing edge of the crate passes the plunger.

As the properly oriented crates continue to move on conveyer 30 they are engaged by the resilient guide bar 32 and urged into side edge alignment with the guide rail 31. As the crates approach the encoding apparatus, a second resiliently biased sensing shoe 81 is engaged and deflected by by the crate to actuate switch 82 and energize a second control circuit. A position sensing device 83 having a plunger 84 positioned to engage flange 72 is resiliently biased to project into the sensing notch 73 as the crate moves along shoe 81. Movement of the plunger 84 into the sensing notch 73 actuates a switch 85 connected in an electric circuit to project the positive stop 34 into the path of the crate to accurately position the crate over the encoding printer 33. After a lapse of a sufficient time to permit the encoder to imprint the desired code signal on the bottom of the crate, suitable time delay means, not shown, retract the stop 34 to permit the crate to continue on conveyer 30 to its desired destination in accordance with the code printed thereon.

While I have disclosed and described preferred embodiments of my invention. [wish it understood that I do not intend to be restricted solely thereto, but that I do intend to include all embodiments which would be apparent to one skilled in the art which come within the spirit and scope of my invention.

I claim:

1. For use in an automatic material handling system including conveyer means and magnetic destination coding and code-reading apparatus, a material handling crate comprising a bottom panel and upwardly directed side panels joined along contiguous edges, and a layer of magnetizable material heremetically sealed in a fixed position within one of said panels, said layer of magnetizable material having a major planar surface substantially parallel to the outer surface of said one panel in position to receive a plurality of magnetic code symbols thereon.

2. The material handling crate defined in claim 1 wherein said layer of magnetizable material is in the form of a substantially flat, thin, rigid sheet of steel.

3. The material handling crate defined in claim 1, wherein said one panel is molded front a nonmagnetic synthetic resin material.

4. The material handling crate defined in claim 3, wherein said layer of magnetizable material is hermetically sealed between two substantially flat sheets of synthetic resin material.

5. The material handling crate defined in claim 4 wherein said layer of magnetizable material and said sheets of synthetic resin material form a substantially rigid structural sandwich, said sandwich being rigidly secured to an outer surface of said one panel whereby said sandwich structure forms a part of said one panel.

6. The material handling crate defined in claim 5, wherein said sandwich is mounted within a recess formed in said one of said panels, said sandwich being rigidly secured within said recess and forming an integral part of said one of said panels.

7. The material handling crate defined in claim 3, wherein said one panel is the bottom panel of said crate.

8. The materialhandling crate defined in claim 7, wherein said layer of magnetizable material comprises a plurality of separate substantially flat, thin sheets of steel arranged in fixed laterally spaced substantially coplanar relation to one another.

9. The material crate defined in claim 7 further comprising spacing means for supporting said bottom panel above the conveyer means to thereby support said magnetizable material vertically above the destination coding and code-reading apparatus. V

I0. ln a crate suitable for use in an automatic material handling system including conveyer means and magnetic destination coding and code-reading apparatus, said crate including a bottom panel molded from a synthetic resin material and upwardly extending side panels, the improvement comprising a recess formed in said bottom panel from one surface thereof and extending only partially therethrough the other surface of said bottom. panel overlying and forming a substantially smooth fluid=tight cover for said recess, a substantially flat sheet of magnetizable material rigidly fixed within said recess with the plane of said sheet of magnetizable material substantiaily parallel to the plane of said bottom panel, and seal means hermetically sealing said. sheet of magnetizable materia! in said recess.

11. The material handling crate as defined in claim 10, the further improvement wherein said recess is formed in the outer surface of said bottom panel with the inner surface extending over and forming a substantially smooth fluid-tight top cover for said recess.

LII

E2. The material handling crate as defined in claim 15, wherein the lower surface of said sheet of magnetizable material is spaced above the bottom surface of said bottom panel.

13. The material handling crate as defined in claim l2. further comprising shoulder means integrally molded with said bottom panel within said recess for supporting said sheet of magnetizable material in fixed spaced relation to said fluidtight cover.

14. The material handling crate defined in claim 11, comprising a plurality of said recesses positioned in laterally spaced relation to one another, with a sheet of magnetizable material rigidly fixed in each of said recesses.

15. The material handling crate defined in claim 14, wherein said seal means comprises a sheet of synthetic resin material covering each of said sheets of magnetizable material, said sheets of synthetic resin material being sealed to said bottom panel around the periphery of said recesses to hermetically seal said sheets of magnetic material within closed chambers in said bottom panel.

16. The material handling crate defined in claim 15, further comprising a plurality of drainage openings extending through said bottom panel in laterally spaced relation with respect to said recesses.

17. The material handling crate as defined in claim 15, wherein said bottom panel is rectangular in shape, and wherein said recesses are arranged in a plurality of rows each containing at least two recesses, with said rows being parallel to and laterally spaced from one side edge of said bottom panel.

18. The material handling crate as defined in claim 17, wherein said recesses are arranged in a rectangular pattern comprising at least three parallel rows of at least three recesses each, said rectangular pattern being concentric with respect to said bottom panel and the side edges of said rectangular pattern being parallel to the side edges of said bottom panel.

19. In the material handling crate defined in claim 18, the further improvement comprising index means carried by one of said panels on an outer surface thereof and accurately located with respect to said rectangular pattern, said index means being positioned to engage sensing means mounted adjacent the magnetic destination coding apparatus for positioning said crate with respect to the coding apparatus.

20. The material handling crate as defined in claim 19, wherein said index means comprises an outwardly directed flange extending along one of said side panels parallel to said bottom panels, and a detent formed in said flange.

21. In a crate suitable for use in a material handling system including conveyer means for delivering articles to a plurality of destinations and magnetic destination coding and codereading apparatus, said crate including a bottom panel and up- I wardly extending side panels joined along contiguous edges,

and a plurality of openings formed in at least one of said panels. the improvement comprising a hollow receptacle having side walls and an end wall molded from a synthetic resin material, means for mounting said receptacle in one of said openings with the outer surface of said end wall substantially coplanar with the inner surface of said one panel, and a magnetizable plate mounted within said receptacle with the plane of said magnetizable plate in fixed substantially parallel rela tion to the plane of said one panel.

22. In the material handling crate defined in claim 21, the further improvement comprising means providing a watertight protective coating for said magnetizable plate.

23. The material handling crate defined in claim 21, wherein said one panel is the bottom panel of the crate, said plurality of openings providing drainage for the crate when the crate is in its normal upright position.

24. The material handling crate defined in claim 21, further comprising closure means for said hollow receptacle, said closure means and said receptacle forming a hermetic seal for said magnetizable plate.

25. The material handling crate defined in claim 24 wherein said closure means comprises a sheet of synthetic resin material overlying said magnetizable plate and bonded to and closing said receptacle.

26. The material handling crate defined in claim 24, wherein a plurality of said receptacles are mounted in openings in said bottom panel in fixed spaced relation to one another.

27. The material handling crate defined in claim 21, wherein said means mounting said receptacle within said one of said openings comprises interlocking detent means formed on the outer surface of said receptacle and the adjacent surface of said one of said openings, said detent means being capable of sufficient resiliently resisted deflection to permit said receptacle to be forceably inserted into said one of said openings.

28. A crate suitable for use in an automatic material handling system including conveyer means and magnetic destination coding and code-reading apparatus, said crate comprising, in combination, a bottom panel molded from synthetic resin material and upwardly extending side panels joined along contiguous edges, an upwardly extending recess formed in said bottom panel from the outer surface thereof and extending only partially therethrough, said bottom panel having an inner surface overlying and forming a substantially smooth watertight top cover for said recess, and code plate support means integrally formed with said bottom panel for supporting a magnetizable metal plate. in substantially parallel-spaced relation to said top cover.

29. The crate defined in claim 28 wherein said code plate support means is adapted to support the magnetizable metal plate intermediate said top cover and the lower surface of said bottom panel and substantially parallel thereto.

30. The crate defined in claim 29, further comprising means for supporting said crate in an upright position on a supporting surface with said bottom panel spaced above and substantially parallel to the supporting surface.

31. The crate defined in claim 30, wherein said bottom panel has a plurality of said recesses formed in its outer surface in spaced relation to one another for supporting a plurality of magnetizable metal plates in spaced parallel coplanar relation to one another.

32. The material handling crate defined in claim 31, wherein said spacing means comprises a stacking ring molded on and projecting downwardly from the lower surface of said bottom panel.

33. In a crate suitable for use in an automatic material handling system including conveyer means, magnetic encoding and decoding apparatus, and means for interrupting movement of crates on the conveyer, said crate including a bottom panel and upwardly extending side panels, the improvement comprising magnetic code-carrying means rigidly mounted in a fixed position on one of said panels, and index means on one of said panels in fixed relation to said magnetic code-carrying means, said index means being located to engage and actuate sensing means to interrupt movement of said crate with said magnetic code-carrying means accurately positioned with respect to the encoding apparatus. 

